US2486857A - Fuel control and air delivery unit for oil burners - Google Patents

Description

A. MACCIHI FUEL CONTROL AND AIR DELIVERY UNIT FOR OIL BURNERS Filed July 11, 1945 Inventor A\do Macchi,

His Attorney.

Patented Nov. 1, 1949 E CONTBQL AND A E IV RY UNrr on on. commas Aldo Macchi, Belleville, N. J., assignor to General Electric Company, a corporation of New York Application July 11, 1945, Serial No. 604 331 4 Claims. (Cl. 1.587 6) The invention relates burner heads, particularly burner heads for introducing fuel and combustion air into a combustion zone and igniting the mixture to establish and maintain combustion therein.

The principal object, is to provide an improved form of oil burner head for extending through a tube into a furnace along with ignition means and having an oil atomizing nozzle aligned inside an air discharge nozzle so as to project coaxial streams of atomized oil and combustion air into a high temperature combustion zone. However, a burner head embodying some of the improvements of the present invention may be adapted for burning other suitable fuels if desired.

Another object is to combine in a burner head an improved form of separately removable inner oil atomizing nozzle with an improved form of removably mounted outerair discharge nozzle.

A further object is to provide the burner head with an improved air flow control and combus tion heat intercepting and dissipating air nozzle structure capable of directing a series of separately distributed streams of air to cool the inner fuel nozzle parts while effectively shielding these inner parts from the radiantheat of combustion so as to lessen the tendency for the oil or other fuel to cake and clog the nozzle passages. I

With some forms of oil burning furnaces operated intermittently under thermostatic control for domestic heating service, it is necessary to provide an electromagnetically controlled oil valve very closely adjacent the inner oil atomizing nozzle for stopping the projection of the oil stream with a minimum of after-drip of residual oil into the combustion zone. A combined elec-v tromagnetic control valve and coaxial oil and air discharge burner head construction is disclosed and claimed in my prior Patent 2,022,513 of lflovember 26, 1 375., and also in the Eaton et al. Eatent 2,048,495 of July 21, 11936, and the present invention provides further improvements therein.

Thus another object is to provide an improved combined control valve and coaxial oil and air discharge burner head by nesting in specially dis tributed and directed air streams Within an outer air discharge nozzle casing, an improved form of combined electromagnetic valve oil atomizing nozzle structure having a relatively small combustion exposed heat absorbing discharge tip portion in close coupled alignment with relatively larger air exposed heat dissipating nozzle body and electromagnetic valve portions such that the whole valve and nozzle structure will run relatively cool after as well as during burner operation.

A further object is to provide an improved sec.- tionalized telescoping form of burner head con? struction with an improved form of inner aligned electromagnetic flow control valve and oil atomize ing nozzle unit that can be easily and quickly de.-.. tached and the parts thereof then readily dis: assembled for individual cleaning and SGIViC? ing without requiring the removal of the outer air nozzle casing and ignition electrodes carried thereby and which will insure reassembly or all the parts in proper cooperating relation and alignment so as to accurately project the coaxial streams of combustion air and atomized oil re.- quired for proper mixture to efiect electric ignie tion and insure clean and efficient combustion.

A specific object is to provide an improved oil burner head having a separately detachable oil atomizing nozzle and associated electromagnetic control valve structure slidably mounted as a unit in a special intermediate air flow directing tube carried inside the combustion air discharge nozzle casing and serving as a mounting socket in align: ment with the air discharge orifice thereof and provided with bafiles and a coordinated labyrinth of air passages for directing concentrated streams of airto efficiently cool the oil nozzle as well as. the mounting socket and correlated air discharge nozzle parts.

Other specific objects and advantages of the invention will become apparent from the following description and the accompanying drawing in which Fig. 1 is a front sectional view of a combined electromagnetic control valve and coaxial oil and air discharge burner head embodying the several improvements of the present invention in a preferred form; Fig. 2 is a partial sectional view in reduced scale of the burner head con.- struction along the line 2-2 in Fig. 1; Fig. 2a is a partial view of the readily detachable electromagnet yoke structure; Fig. 3 is a partial sectional View along the line 33 in Fig. 1 and Fig. 4 is a partial sectional view along the line %4 in Fig. 1, showing more clearly the details of COD? struction of the various parts.

In Fig. 1 the improved burner head of the present invention is indicated generally by the reference character l0 and is shown removably mounted within a well ll formed by the cylindrical tube l2 extending between the top plate It and the crown sheet M of a boiler furnace to enable coaxial streams of atomized oil and come bustion air to be projected along the axis a, of the circular opening 15 into the boiler combustion chamber. The improved burner head I is provided with an outer air nozzle tube or cylindrical casing l6 having an offset axis b and provided with a peripheral or outwardly extending eccentrio mounting plate, flange, or rim ll at the upper end thereof so that rim H may be removably secured by means of the bolts E8 to seal the upper end of the boiler well ll gas tight, preferably with a suitable sealing gasket l9 interposed therebetween. Combusion air is supplied from a suitable blower or other source, not shown, to the upper end of the air nozzle tube or casing 16 through the air supply pipe 25. The air supply pipe 28 detachably surrounds the air inlet orifice Zla of the separately removable cover plate 2! that serves to open or close the upper end of tube It and is secured in position by the screws 22.

The lower end of the air nozzle tube or outer casing H is provided with a series of lateral cooling air outlet notches or openings 23 directly adjacent the combustion radiant heat intercepting member or plate 24 preferably in the form of a circular overlapping disk that is secured eccentrically to and extends across the lower end of the air nozzle tube or casing l6 and is provided with the central air discharge orifice 25 for projecting a stream of combustion air along the axis a through the opening 55 into the high temperature combustion zone. As shown in Fig. 2, the circular overlapping heat intercepting disk or plate 24 is of slightly smaller diameter than the cylindrical boiler well l2 so as to telescope readily therein and provide a narrow annular space 26 around the periphery thereof for restricted fiow of the cooling air passing through openings 23.

The combustion heat intercepting and air orifice discharge disk or plate 24 carries an inner air fiow control tube 21 that also serves as a mounting socket for the oil valve and atomizing nozzle unit 34. Tube 21 is mounted upon and extends upwardly from plate 24 inside of the outer tube or casing 55 in axial alignment with the air discharge orifice 25. This inner air fiow control tube 2! is provided with a series of lateral air flow openings 28 directly adjacent the heat intercepting plate 24 through which concentrated streams of air are supplied to the air discharge orifice 25. An axially displaced series of lateral air fiow openings 29 are provided in the inner fiow control tube 21 and an inner air flow control and heat intercepting socket bafile 30 is extended across tube 2'! so as to cause a fiow of cooling air out of the tube 2? through the series of openings 29. An outer air flow baflie 3| is secured to the inner tube 2'5 preferably by welding in a position to cause a flow or" cooling air into the tube through the open end slot 32. As shown in Fig. 2 the baiile 39 is substantially crescentshaped so as to extend around a substantial portion of the tube 66, and thereby cause a flow of air into tube i5 through the series of elongated openings or slots 33. In claiming the invention the above-described air nozzle tube or cylindrical casing It? may be termed a combustion air tube, or a combustion air supply tube or an air flow tube or a cylindrical air fiow tube. Likewise the inner air flow control tube 21 that serves as a mounting socket may in claiming the invention be termined a socket, a heat dissipating and mounting tube or an air-cooled or heat dissipating tube as it serves as such.

For mutual cooperation with the improved heat intercepting and air discharge nozzle structure just described, the improved combined oil atomizing nozzle and electromagnetic control valve unit 34 is of special elongated tubiform construction to telescope inside the outer air nozzle tube 55 and slide into interlocking engagement with the mounting socket formed by the inner tube 2'! and its socket baffle 30 so as to constitute a separately detachable unit that is efiectively cooled by the distributed air streams within tube l6 and can be readily removed and all the principal parts thereof quickly disassembled for inspection, servicing and repair. To enable these various advantages to be obtained the improved combined oil atomizing nozzle and electromagnetic valve unit 34 is provided with a central or intermediate specially formed tubular combined oil flow control valve body and oil and air nozzle connection block 38 having a lateral connection socket 39 for sweating the end of the laterally offset oil pressure supply pipe or tube 45 therein and a similar lateral socket 4! for sweating the end of the laterally offset air pressure supply pipe 42 therein. The flow of oil from the supply pipe 45 is controlled by the axially movable oil valve 43 to admit oil through the oil strainer 44 mounted in the chamber 45 that extends axially through the elongated valve body 38. The air passage 46 is laterally offset in the body 38 from chamber 45 to conduct air under pressure from pipe 42.

A correlated oil and air flow metering member or disk 50 having a central oil metering orifice 5i, and a series of symmetrically disposed air metering orifices 52 interconnected by the groove 53 as shown in Fig. 3 is disposed at the end of the valve body 38 and maintained in predetermined alignment therewith by means of the guide pin or dowel 41. The proportional oil and air discharge through the metering orifices 5| and 52 is initially mixed in a chamber 48 formed by the cup-shaped member 54 having a central restricted outlet orifice 55 into a secondary oil and air mixing chamber 55 formed within the nozzle tip or nut 51 that is provided with the enlarged mixed oil and air atomizing discharge orifice 58 for projecting a stream of atomized oil in coaxial alignment with the stream of air discharged through the combustion air discharge orifice 25. The oil atomizing nozzle tip or nut 51 is screw threaded to the lower end of the valve body 38 and thus serves to clamp the orifice member 50 and the mixing cup 54 in close engagement to insure accurate metering and mixing of the oil and air.

The discharge end 59 of the oil atomizing nozzle tip 5'! is of materially reduced diameter so as to expose only a small area to the radiant heat from the high temperature combustion zone. This reduced diameter end 59 of nozzle tip 5! extends through the heat intercepting and air fiow bafile 30 and the baffle 30 is provided with the pressed out curved fingers Gil so as to provide a sliding socket mounting for accurately posl tioning the oil atomizing nozzle tip M in coaxial alignment with the air discharge orifice 25.

The oil fiow control valve 43 is provided with an improved form of operating electromagnet, indicated generally by the reference character 62, that is adapted to be removably mounted on the end of the valve body 38 opposite the nozzle tip 51. The headed stem 63 of valve 43 has a suitable lost motion operating connection with the magnetic operating plunger 64. Plunger 64 operates within a sealing and guide tube 65 having a flange 66 for clamping into fiuid tight seal- @AQQQQZ he engagement withhe rea ea ns i? at he alve bq byme nste g he threa ed bellow mag e ic" u fii c ur unqe u e-ta Mae: netic nut w etei r ar ieeth uati sh: 1' 59 which r '5 ti fi fli' fily 12. W upper end of the inner air flow control" anjd socliet mountingtube -21 to support, the whole, rernqvable iB- ra y h edee iq i he nset a ia-qt tube 21 are turned inwardly as shownlso las to l se n w e e ed e -a r, b-emacnetic nut 6 8 and thereby insure to ther. with the curved socket fin ers fill the axial alignerit of the whole oil atQmiZlIlg nozzle structure with axis a of the air discharge orifice. 315:.

As shown in Fig. 2, the mountingwasher dais provided with a pair of fingers It forquicl z; detachabl interlocking engagement with the lllfig-r netic yoke "12, as indicated in Fig. 2a. The mag? netic yoke 72 extends over and around the electromagnet energizing windings of coil 13 and the compression spring 1d and cooperating magnetic sleeve 75 are provided for resiliently holding the windings or coil it, in operating position surrounding the sealing tube55 to attract thevalve operating plunger 54. Ereferably a compression spring l6, is provided at the upper end of tube 65 to serve as aresilient stopior absorbing the shock and quieting the vibrations of plunger fill when the electromagnetic operating winding or coil I3 is energized with alternating current.

The oil supply tube 40 and the air supply tube 42 are in vertical alignment at their bent-over ends connected with the valve body 38 so as to slide directly into the open end slot 32 provided in the inner tube 2! but are suitably formed so as to extend upwardly through the eccentric space provided along one side 'of the outer air nozzle tube or casing E6 in substantially parallel alignment as indicated in Fig. 2. Thus each tube is in go od heat transfer relation with the air flow through casing M5. to dissipate heat therein Each tube extends through a suitable. tightly fitting opening formed in the removable cover 2-! so that this cover cap can substantially seal the upper end of the air nozzle casing air tight. The rernovable clamp Bl! is provided for securingboth the oil tube All and the air tube 42; in place and prefe erably is. plfqvided with a suitable extension- 8 tightly extending through the cover plate 2| so that the clamp may be fastened down. by tightening the bolt 82. Similarly, the electrical CQHHBC-r tion lead wires :33 for energizing coil 13 extend through a suitably formed tightly fittingopening 34in the removable cover plate 2| As shown in Figs. 1 and 2, the improved burner and coaxial discharge orifice 25 by clamps tl, 88 and screws as, The high voltage insulators 86 extend through. and preferably are sealed in suitable holes formed the eccentric supporting peripheral plate, flange, or rim ll of the air noz zle casing 5. The heat intercepting plate M is provided with suitable spaced apart openings 98 through which the high voltage electrodes 8% extend so as to shield the insulators $6 from heat as ll tram, 91 pray, arthen. qe aeit er, the like.

h, he mmerse; bead L L qen t ue ae as described above, a trearn q f at o is discharged from the orifice 58 qt t a 51 along em n axi 1. utqthe i h @6 2 na Qf; qmbustio he v l e.- iti ensued by s za i 0 erati g sl qtrq i e ae 6t:- is'aex ends f ueh h e ter; o tsire u r erm ne i- .h q e i he il row i ntol mlw tiq mbst- Qfheu and also constitutes theaxis of, the welt l l f by. the, cylindrical tube 1.2, as well as, the ants or e. inset ai entra t be nd m u ti s et h m e. the axis pass s WP. center of the. circular air discharge orifice 1;} the heat intercepting plateizi l and also const t tes h n t d n axis f he im ve ans at x a l l n wmb eed il emi ins n z e. and c rb a c. wa taalve t aws-e when mounted in socket 21 Buttheaxisb of thecyline ducal air nozzle casing i6 is s lac d fl at om t ma a is sh n, m re e ear the sectipnal, View of, Fig. 2 Sp as, to, provide an Offset e e i spate f nest ng he'qi suppl tube a a d. he urel t be 42 therein, the eccentric cat n O the a im-ale tuba I in i he l I 2 e. mar as a qaqs aeff e eeesm trio Space w th th wel M fer; et-tine. the-pai f sp ced, apart h h v lta e i n n n l trodes 85 with their high voltage n sul a 8'5 adequately spaced away from the x x/ alls, 11 or the boiler w l as we l theaa l at h i be It r proper n lllai n.-. Th e ee q le -w are damned ,awi .i l ,s H re a i h ESP??? att e il di harsenwzle i nd th e m u i a n: d s uise and and thus carried outside the air nozzletube it.

e c mbu t cn a up l ed. and r u h. h u ly pi e 1%. pass s. throu h, the et ing orifi 2 t, and i d re di ec l 1 9 and around all t e expo ed eer e oi h t cperat ns le r mae et ha arei rablv ed n li ment. with. th a r ia i .r Me- A a lttbe el qtr e l y and generated heat of the op ing ele tr is r pidl diss pated, mm. 5 .9 illQQlIlit s Preven ex es iv t mpera ure ri e. e these Pa he a fl w de d by seir aa net 62 o to ass m n h at exchange a onew ihtli exte d a i t eo l sup: Ply sine Bland e suppl i e ty and hus servsto educe h tem re ur i itheee tse to h r e t-shavedhaf le i. the inner ube l v Her ha Q the, h s s f t l w ough 1 2 a d he ser es slots 33 a r pa n uqces ve uad ature re a i n. 5 as 9 r vide. ceeeeairat d strea q a r. ir edup n h me sed? with and n valve dy nd. qqaneetimh gpk. he n er ube 1- h sw nqeut i d air er to a idly d. fi fr m} all the ex sur ace enul shamew r particularly the inn r val eb we block 38 d e s? the heat. wiri a hi h e e it a r flew Wau h the r largely exposed to the heat radiated through the air discharge orifice 25 from the furnace combustion chamber.

Some of the air admitted into casing l passes directly along the inside surfaces thereof since the crescent-shaped baffle 3| does not entirely obstruct the air fiow space. This serves to maintain the tube I6 well below the temperature of the surrounding boiler Well l2 and prevents heat radiated from well I2 reaching the inner oil nozzle parts. A portion of the heated air is exhausted from tube I 6 through the series of radial air flow passages 23, thus further serving to wipe heat from the inner surfaces of the heat intercepting disk 24. The remainder of the air is admitted through the series of openings 28 to provide a radially concentrated blast directly adjacent the exposed end of the nozzle tip 57 before passing through the air discharge orifice 25 into the combustion chamber. In this way heat is rapidly absorbed from all of the various burner head parts adjacent the oil and air discharge orifices and is returned to the combustion chamber. As a result a highly efficient cooling of the inner oil valve and nozzle parts is obtained with but a relatively small total flow of combustion air required through the air nozzle casing I6 since the total air flow is subdivided and directed in a series of separately distributed streams into intimate heat absorbing relation with the several parts to be cooled. Consequently, all these parts will run relatively cool during burner operation when combustion air is supplied under pressure through the air supply tube 20 and also after the valve 43 is closed to stop burner operation. In the latter case the slight natural draft through the furnace serves to produce sufficient flow of air through the air nozzle tube I6 to continue dissipation of the heat that may be subsequently absorbed by the burner head parts from the boiler well I2 or the highly heated radiant refractories, or the like, with which the high temperature combustion zone of the furnace may be provided.

Several practical advantages in servicing and maintenance are obtained with the improved burner head construction of the present invention due to the ready removability of the electromagnetic oil flow control valve and atomizing nozzle unit 34 for inspection, cleaning and repair i of all the parts thereof. This is readily accomplished simply by removing the cover plate 2| and disconnecting the leads 83, the oil and air supply tubes 46 and 42, and removing the holding down bolt 82 and the tube clamp 86. Thereupon the entire electromagnetic valve and atomizing nozzle unit 34 is free to slide upwardly out of the socket mounting thereof provided by the inner tube 21 and through the open air supply end of the air nozzle tube or casing l 6. With all parts of the valve and nozzle unit thus readily accessible, the magnetizing winding it of the valve operating electromagnet may be readily removed simply by compressing spring I4 and unlatching the magnetic yoke 12. Then by applying standard wrenches to the outside hexagonal surfaces of body 33 and the magnet nut member 68, the latter is readily unscrewed so that the sealing tube 65 can then be removed to provide full access to the inner oil valve 43 and its operating magnetic plunger 64.

Likewise, by applying standard wrenches to the hexagonal outer surfaces of the enlarged portion of the nozzle tip or nut 51 and the valve body 38, the nozzle tip is readily unscrewed to provide access to the oil and air orifice member or disk and to the mixing cup member 54 as well as the interior passages of body 38 and the nozzle tip 51. When strainer 44 is removed, all of the inner oil and air flow passages and chambers of the combined fiow control valve and atomizing nozzle are fully exposed for inspection and cleaning of any carbonized oil or accumulated sludge or dirt therein.

In case it is desired to change the oil burning rate of the burner head all that is necessary is to substitute duplicate atomizing nozzle tip parts 50, 54, and 51 and cover 2| that are properly calibrated and correlated for the air flow and oil fiow required.

All of the various parts of the combined valve and atomizing nozzle structure after inspection, servicing or replacement may be readily reassembled in proper cooperating relation and the whole unit returned into proper coordinated relation With the combustion air nozzle parts simply by sliding the valve nozzle unit 34 through tube it into the mounting socket provided by the inner tube 21. The oil and air supply pipes 40 and 42 slide into the slot 32 and the nozzle 5'! slides into self-centering relation with the curved fingers of the baffle 36. Also the magnetic member 68 slides within the inturned edges at the upper end of the tube 2'! so as to properly align the whole electromagnetic and valve unit along the axis a of the combustion air discharge orifice 25. The washer 59 engages with the top of tube 21 to provide proper spacing of the oil discharge orifice 58 inwardly of the combustion air discharge orifice 25. Consequently, all these parts are returned into proper coordinating relation to project the coaxial streams of atomized oil and combustion air into the combustion zone required for ready ignition by the electrodes 35 as Well as efficient and clean combustion in the high temperature combustion zone.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a burner mounting tube having a combustion zone adjacent the inner end thereof, ignition elements extending through said tube into said zone, a combustion air supply tube having a peripheral mounting plate at one end thereof sealing the outer end of said burner mounting tube and provided with means for mounting said ignition elements in nested relation with said air supply tube inside said mounting tube, means carried by said plate for providing a restricted air inlet orifice for said air supply tube, means providing a restricted air outlet orifice at the inner end of said air supply tube for projecting a stream of air into said combustion zone, said air supply tube being provided with lateral openings for discharging a part of the inlet air to cool the space between said tubes, and an elongated tubiforrn combined oil atomizing nozzle and electromagnetic oil flow control valve unit having laterally offset oil and air supply pipes extending through said mounting plate and provided with mounting means for nesting said unit inside said air tube adjacent said outlet orifice to project a stream of fuel through said outlet orifice in predetermined relation with said ignition elements to be ignited thereby.

2. In combination, a cylindrical burner mounting tube having a combustion zone adjacent the inner end thereof, a cylindrical combustion air supply tube provided with lateral air discharge openings and having projecting annular membars at opposite ends thereof for removably telescoping said air tube inside said mounting tube with one of said annular members sealing the outer end of said mounting tube and having an opening for admitting combustion air to said supply tube and the other of said annular members forming a heat shield and providing a restricted orifice coaxial with the axis of said mounting tube for projecting a stream of air into said combustion zone, and an elongated tubiform combined oil nozzle and electromagnetic flow control valve unit having laterally offset oil and air supply pipes extending through said one annular member for removably nesting said unit inside said air tube adjacent said orifice to project a stream of fuel coaxial with said air stream.

3. In combination, a burner mounting tube having a combustion zone adjacent the inner end thereof, a combustion air supply tube having a peripheral mounting plate at one end thereof for removably telescoping said air tube inside said mounting tube and sealing the space therebetween, said plate having an opening therein for admitting combustion air to said supply tube, a heat intercepting plate overlapping the inner end of said air tube and provided with a restricted orifice for projecting a stream of air into said combustion zone, a socket mounted on said heat intercepting plate in alignment with said orifice, and a combined fuel nozzle and electromagnetic flow control valve unit removably mounted in said socket for projecting a stream of fuel coaxial with said air stream.

4. In combination, a burner mountin tube having a combustion zone adjacent the inner end thereof, a pair of ignition electrodes extending through said tube adjacent one side thereof into said zone, a, combustion air supply tube havin clamping means on one side thereof for adjustably clamping said electrodes thereon and provided with a peripheral mounting plate at one end thereof for removably nesting said air tube and ignition electrodes inside said mountmg tube and sealing the outer end of said mounting tube, said air tube having an air inlet orifice at said one end thereof and having lateral openings for discharging a part of the inlet air to cool the space between said tubes, a heat intercepting plate overlapping the inner end of said air tube and provided with a restricted orifice arranged in communication with said air tube for projecting a stream of air into said combustion zone in predetermined relation with said electrodes, said heat intercepting plate having a socket mounted thereon in alignment with said orifice, and an elongated tubiform combined oil atomizing nozzle and electromagnetic flow control valve unit having laterally offset oil and air supply pipes extending through said mounting plate for mounting said unit in said socket to project a stream of fuel coaxially with said air stream.

ALDO MACCHI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,170,976 Kroutzberg Feb. 8, 1916 1,323,778 Lemp Dec. 2, 1919 1,551,731 Charter Sept. 1, 1925 1,640,728 Scott Aug. 30, 1927 1,660,075 Holden et a1 Feb. 21, 1928 1,664,616 French Apr. 3, 1928 1,701,218 Seaboldt Feb. 5, 1929 1,976,097 Sharp Oct. 9, 1934 2,022,513 Macchi Nov. 26, 1935 2,048,495 Eaton et a1 July 21, 1936 2,124,443 Wotring July 19, 1938 2,162,051 Ballman June 13, 1939 2,242,787 Lieberherr May 20, 1941 FOREIGN PATENTS Number Country Date 101,859 Sweden June 23, 1941

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